---
layout: "default"
title: "Operator: -="
description: "Swift documentation for the '-=' operator."
root: "/v2.0"
---

<code class="language-swift">infix operator -= {
    associativity right
    precedence 90
    assignment
}</code>

<h3>Declarations</h3>

<div class="declaration" id="func-mnseq-inout_-double-rhs_-double">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-double-rhs_-double">func -=(<wbr>inout:<wbr> Double, rhs: Double)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-double-rhs_-double"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Double, rhs: Double)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-float-rhs_-float">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-float-rhs_-float">func -=(<wbr>inout:<wbr> Float, rhs: Float)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-float-rhs_-float"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Float, rhs: Float)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-float80-rhs_-float80">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-float80-rhs_-float80">func -=(<wbr>inout:<wbr> Float80, rhs: Float80)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-float80-rhs_-float80"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Float80, rhs: Float80)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-int-rhs_-int">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-int-rhs_-int">func -=(<wbr>inout:<wbr> Int, rhs: Int)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-int-rhs_-int"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Int, rhs: Int)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-int8-rhs_-int8">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-int8-rhs_-int8">func -=(<wbr>inout:<wbr> Int8, rhs: Int8)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-int8-rhs_-int8"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Int8, rhs: Int8)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-int16-rhs_-int16">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-int16-rhs_-int16">func -=(<wbr>inout:<wbr> Int16, rhs: Int16)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-int16-rhs_-int16"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Int16, rhs: Int16)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-int32-rhs_-int32">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-int32-rhs_-int32">func -=(<wbr>inout:<wbr> Int32, rhs: Int32)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-int32-rhs_-int32"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Int32, rhs: Int32)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-int64-rhs_-int64">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-int64-rhs_-int64">func -=(<wbr>inout:<wbr> Int64, rhs: Int64)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-int64-rhs_-int64"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: Int64, rhs: Int64)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-uint-rhs_-uint">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-uint-rhs_-uint">func -=(<wbr>inout:<wbr> UInt, rhs: UInt)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-uint-rhs_-uint"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: UInt, rhs: UInt)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-uint8-rhs_-uint8">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-uint8-rhs_-uint8">func -=(<wbr>inout:<wbr> UInt8, rhs: UInt8)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-uint8-rhs_-uint8"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: UInt8, rhs: UInt8)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-uint16-rhs_-uint16">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-uint16-rhs_-uint16">func -=(<wbr>inout:<wbr> UInt16, rhs: UInt16)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-uint16-rhs_-uint16"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: UInt16, rhs: UInt16)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-uint32-rhs_-uint32">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-uint32-rhs_-uint32">func -=(<wbr>inout:<wbr> UInt32, rhs: UInt32)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-uint32-rhs_-uint32"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: UInt32, rhs: UInt32)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-inout_-uint64-rhs_-uint64">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-inout_-uint64-rhs_-uint64">func -=(<wbr>inout:<wbr> UInt64, rhs: UInt64)</a>
        
<div class="comment collapse" id="comment-func-mnseq-inout_-uint64-rhs_-uint64"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=(inout lhs: UInt64, rhs: UInt64)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-memory-inout_-unsafemutablepointer-memory-rhs_-int">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-memory-inout_-unsafemutablepointer-memory-rhs_-int">func -= &lt;Memory&gt;(<wbr>inout:<wbr> UnsafeMutablePointer&lt;Memory&gt;, rhs: Int)</a>
        
<div class="comment collapse" id="comment-func-mnseq-memory-inout_-unsafemutablepointer-memory-rhs_-int"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=&lt;Memory&gt;(inout lhs: UnsafeMutablePointer&lt;Memory&gt;, rhs: Int)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-memory-inout_-unsafepointer-memory-rhs_-int">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-memory-inout_-unsafepointer-memory-rhs_-int">func -= &lt;Memory&gt;(<wbr>inout:<wbr> UnsafePointer&lt;Memory&gt;, rhs: Int)</a>
        
<div class="comment collapse" id="comment-func-mnseq-memory-inout_-unsafepointer-memory-rhs_-int"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=&lt;Memory&gt;(inout lhs: UnsafePointer&lt;Memory&gt;, rhs: Int)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-t_-integerarithmetictype-inout_-t-rhs_-t">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-t_-integerarithmetictype-inout_-t-rhs_-t">func <wbr>-= &lt;T : _IntegerArithmeticType&gt;(<wbr>inout:<wbr> T, rhs: T)</a>
        
<div class="comment collapse" id="comment-func-mnseq-t_-integerarithmetictype-inout_-t-rhs_-t"><div class="p">
    <p>subtract <code>lhs</code> and <code>rhs</code> and store the result in <code>lhs</code>, trapping in
case of arithmetic overflow (except in -Ounchecked builds).</p>

    <h4>Declaration</h4>    
    <code class="language-swift">func -=&lt;T : _IntegerArithmeticType&gt;(inout lhs: T, rhs: T)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-t_-strideable-inout_-t-rhs_-t-stride">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-t_-strideable-inout_-t-rhs_-t-stride">func <wbr>-= &lt;T : Strideable&gt;(<wbr>inout:<wbr> T, rhs: T.Stride)</a>
        
<div class="comment collapse" id="comment-func-mnseq-t_-strideable-inout_-t-rhs_-t-stride"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=&lt;T : Strideable&gt;(inout lhs: T, rhs: T.Stride)</code>
    
    
</div></div>
</div>
<div class="declaration" id="func-mnseq-t_-unsignedintegertype-inout_-t-rhs_-t-disallowmixedsignarithmetic">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-mnseq-t_-unsignedintegertype-inout_-t-rhs_-t-disallowmixedsignarithmetic">func <wbr>-= &lt;T : UnsignedIntegerType&gt;(<wbr>inout:<wbr> T, rhs: T._DisallowMixedSignArithmetic)</a>
        
<div class="comment collapse" id="comment-func-mnseq-t_-unsignedintegertype-inout_-t-rhs_-t-disallowmixedsignarithmetic"><div class="p">
    

    <h4>Declaration</h4>    
    <code class="language-swift">func -=&lt;T : UnsignedIntegerType&gt;(inout lhs: T, rhs: T._DisallowMixedSignArithmetic)</code>
    
    
</div></div>
</div>
